Solar panels explained: this blog covers how solar panel efficiency is measured. Is it easy to measure? Yes, we can measure the efficiency of solar panels using numeric values. It requires the amount of sunlight and the energy produced. These calculations are not straightforward for everyone, so most people assume efficiency is difficult to work out. To go deeper, see our guide on solar panel efficiency.
How efficient are solar panels?
Most solar panels are between 15% and 20% efficient, with some exceptional brands sitting outside this range. High-quality solar panels will easily surpass 22% efficiency, although the majority of panels on the market are less than 20% efficient. If you want to compare the leaders, read about the most efficient solar panels.
What factors affect a solar panel’s efficiency?
Many factors influence the efficiency of solar panels. Let us look at some of the most important ones:
- Intensity of sunlight: The amount of sunlight differs throughout the day, affecting how effectively a panel performs. Solar panels produce more electricity in the afternoon, when the sun is at its brightest and they can absorb more energy.
- Temperature: Solar panels often cannot work properly at higher temperatures. Heat build-up is a common issue in warm climates, and it can reduce energy production by 10% to 25%. Heat increases the conductivity of the photovoltaic cells’ semiconductors, resulting in a charge imbalance and a decreased electrical field.
- Size of panel: Efficiency also varies with the power rating and total panel area. Larger panels use larger cells, increasing the cell surface area and generally making the panels more efficient.
- Cell material: Efficiency also depends on the structure of the cells and the material used in production. Whether a cell is P-type or N-type defines its quality and plays a vital role in overall efficiency.
Final words
To summarise, you can rarely determine real-world efficiency yourself, even with the formula. It helps to have professionals advise you, as they have experience comparing the brands available. If you are weighing up your options, our overview of the pros and cons of solar panels is a good place to start. When you are ready, get a free quote and our team will answer any questions about solar panel efficiency.